Background: Several epilepsy-specific quality of life questionnaires have been developed. One of them is quality of life in epilepsy-89 version. The objective of this study was to develop a Persian version of QOLE-89 and confirm its psychometric properties.
Materials and methods: Participants were 75 patients with epilepsy. The quality of life questionnaire was adapted to Persian language through a translation and translation-back procedure. Internal consistency by Cronbach's α, was determined and construct validity was assessed by correlation with GHQ-12 and BDI-PC and discriminant validity was confirmed by comparing scores for known groups.
Results: Reliability based on internal consistency (Cronbach's α) for QOIE-89 was 0/96 and for 17 subscales was varied form 0/70 to 0/89 and Test-retest reliability (Pearson's correlation coefficient) for the Farsi version of the QOLIE-89 ranged from 0.75 to 0.88. Total score of QOLIE-89 discriminated well between the patients according to depression severity and drug resistance and seizure controllability. Correlation between the total scores, BDI-PC and GHQ-R to confirm construct validity was 0/55 and 0/63, respectively.
Conclusion: In this cross-sectional survey, Persian version of the QOLIE-89 was reliable and showed properties supporting the construct and discriminant validity at a level comparable with the original and some other versions. Thus, this questionnaire has suitable properties in Iranian population and can be used in clinical trials with epileptic patients.
Keywords: Epilepsy; QOLIE-89 validity; psychometric properties; quality of life; reliability; seizure; sensitivity; specificity.